JPH04182361A - Repairing material for spraying - Google Patents

Abstract

PURPOSE:To improve applicability, adhesion and durability by incorporating an org. binder contg. powdery phenol resin, a phosphoric acid-based binder and a lime compd. into a refractory material. CONSTITUTION:A refractory material such as magnesia is prepd. and 100 pts.wt. of the refractory material are blended with 5-20 pts.wt. org. binder contg. >=40wt.% powdery phenol resin such as tar, 0.3-4 pts.wt. phosphoric acid-based binder such as sodium hexametaphosphtate and 2-8 pts.wt. (expressed in terms of CaO) lime compd. such as slaked lime in >=1.3 ratio of CaO to P2O5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spray repair material for molten metal containers for pig iron making and steel making, and more specifically, it can be applied using a conventional spray machine, and has excellent adhesion and durability. The present invention relates to a spray repair material that is comparable to baked-on materials and has superior properties.

[Prior Art] Dry spraying repair methods have been generally employed for repairing molten metal containers for pig iron and steel production, such as converters, pig iron mixers, ladles, and tundishes. In this method, the spraying material is pneumatically fed from a hopper to the spraying machine, and the spraying material and water are mixed at the tip of the spraying machine to form a slurry, which is sprayed onto the repaired area and adheres to it. The binder used in this sprayed material is generally a silicic acid-based or a phosphoric acid-based binder since water is used.

In addition, with the recent adoption of carbon-containing bricks, spraying materials now contain carbonaceous materials, and there are also spraying methods that use organic resins as binders and do not use water (for example, Japanese Patent Laid-Open No. 54-125105 Public bulletin).

Furthermore, baking materials using organic resin as a binder have been successfully used for repairing molten metal containers for steel manufacturing (for example, Japanese Patent Laid-Open No. 139068/1983).

[Problem to be solved by the invention] When using an inorganic binder in hot spraying repair where the temperature of the repaired wall surface is high, it is necessary to cool the wall surface in order to increase the adhesion rate of the material. I have to attach it. The construction body obtained by spraying with high moisture content has a high porosity, and a large amount of an inorganic binder with a low softening temperature is used, resulting in a product with low durability as a repair material. Furthermore, there is a drawback that when high moisture is sprayed onto a vertical wall surface, a large amount of material flows down.

Conversely, if the water content is reduced, the rebound loss of the material will increase.

When non-aqueous blowing materials do not use water, pitch or phenolic resin is used as a binder, so hot spraying produces smoke due to incomplete combustion of the binder, which is an environmental problem as well as visual inspection. The problem with spraying is that it makes it difficult to understand the situation. Additionally, when using water, the spray water can also be used to cool and protect the nozzle of the spray machine, but for spray repairs that do not use water, cooling of the spray machine nozzle must be considered separately.

Further, although the above-mentioned baked-on materials are considerably superior to sprayed materials in terms of adhesion rate and durability, they have drawbacks such as poor workability and inability to apply to sloped areas.

[Means for Solving the Problems] The present inventors have overcome the above-mentioned problems and have conducted various studies on spray repair materials similar to hardened steel materials that can handle the temperature of the repaired wall surface from hot to cold. As a result, the present invention was completed, and the main points of the present invention are: 5 to 20 parts by weight of an organic binder containing 40 parts by weight or more of a phenol resin, and a phosphoric acid binder per 100 parts by weight of the fireproof material. It is a blow (-1 repair material) characterized by containing 0.3 to 4 parts by weight and 2 to 8 parts by weight of a lime compound in terms of CaO.

The fireproof material used in the hot spray repair material of the present invention is selected depending on the material of the molten metal container to which it is applied. In other words, alumina, silica,
Acidic or neutral oxide refractory materials such as alumina, spinel, zircon, and zirconia are used in converters, molten steel ladle, kundish, etc., while basic or neutral refractory materials such as magnesia, alumina, and spinel are used in converters, molten steel ladle, kundish, etc. One or more of the following may be used. In addition, non-oxide refractory materials such as silicon carbide and silicon nitride, and carbonaceous materials such as graphite can also be added as appropriate.

The particle size of the refractory material used may be within the particle size range of ordinary spray repair materials.

Organic binders are those that polymerize at high temperatures to form carbon bonds, and include carbon resins such as pitch, tar, asphalt, and giltstone, or phenolic resins, melamine resins,
It is a resin such as urea resin, and is used in combination with phenolic resin and other organic binders.

The amount of organic binder used is 5 to 100 parts by weight of the fireproof material.
The amount is 20 parts by weight. If the amount used is less than 5 parts by weight, sufficient carbon bonds will not be formed, and if the amount exceeds 20 parts by weight, a dense construction will not be possible. Furthermore, the organic binder needs to contain 40% by weight or more of phenolic resin. If the content of the phenolic resin is less than 40% by weight, as described above, the phosphate will harden first and carbon bonds will not be sufficiently formed.

As the phosphoric acid binder, various phosphoric acids, condensed phosphoric acids, and their alkali metal salts, alkaline earth metal salts, aluminum salts, etc. can be used.

The amount of the phosphoric acid binder used is 0.3 to 4 parts by weight per 100 parts by weight of the refractory material. If the amount is less than 0.3 parts by weight, the agglomeration state of the slurry is weak and shape retention is difficult to develop, and if the amount exceeds 4 parts by weight, curing by the phosphate will proceed and carbon bonds will not be sufficiently formed. , both are unfavorable.

Next, the lime compound is slaked lime, quickstone, carbonate lime, etc., and 2 to 8 parts by weight, preferably 3 to 7 parts by weight of CaO is used per 100 parts by weight of the refractory material.

Further, the ratio of CaO/P:05 is set to 1.3 or more. If the amount of CaO is less than 2 parts by weight, the width of the water that forms the agglomerated state of the slurry will be narrowed, resulting in a decrease in workability during spraying, and if it exceeds 8 parts by weight, the physical properties of the construction object will deteriorate, so it is preferable. do not have. Also, CaO/P2
By setting the ratio of 0=to 13 or more, the range of moisture that forms the agglomerated state of the slurry is widened, and workability during construction is greatly improved.

In addition to the above-mentioned components, the spray repair material of the present invention contains various fibrous materials for the purpose of preventing peeling of the construction body, and metal powder to improve the strength of the construction body and prevent oxidation of carbon bonds. Of course, other additives used in ordinary spray materials can also be used.

The present invention is characterized in that the spraying machine can be a dry spraying machine of a nozzle mix type, which mixes water and material using a nozzle, which is currently in general use. The amount of water added is determined by the type of refractory material, type of bonding material, and temperature of the repaired wall. Moisture is added for the purpose of cooling the nozzle with water, preventing the organic binder from burning due to furnace heat and emitting smoke, and imparting shape retention to the slurry through interaction with the phenolic resin, phosphate, and lime compound. Basically, the amount of water added can be reduced as the temperature increases and the carbon bond formation reaction of the organic binder becomes faster, but since water also has the role of cooling the nozzle, it is necessary to add more than a certain amount. is necessary.

The water introduced into the nozzle is mixed with the material pneumatically fed from the hopper to form a slurry, which partially evaporates inside the nozzle to cool the nozzle. During the subsequent injection, water is involved, so even if an organic binder is used, a film of water is formed and the spray reaches the wall surface without emitting smoke. The material that reaches the repaired wall surface is firmly fixed to the wall surface due to weak curing by the phosphoric acid binder, which begins to harden due to the action of water during injection, and subsequent hardening of the organic binder. At that time, most of the water has evaporated, so the bonding of phosphates will continue to develop.Since the temperature of the material does not inhibit the polymerization of organic binders, refractory materials are made of carbon bonds, which make them strong. Becomes a body.

In this way, in the present invention, water acts to cool the spray machine nozzle, transport the material, prevent smoke from the organic binder, and initiate the reaction of the phosphoric acid binder, which has the advantages of dry spraying and wet spraying. It has both.

[Function] While conventional spray materials utilize the curing action of inorganic binders such as phosphates and silicates to develop adhesion and hardenability, the spray materials of the present invention utilize organic binders. It is characterized by the fact that the carbon bonds produced by the process exhibit adhesion and hardenability of the construction body. In other words, unlike conventional spraying materials, it is based on a repair material called baking material, which is a refractory material kneaded with tar pitch and used to repair the horizontal surfaces of converters. It is provided as a repair material that can be applied to vertical surfaces.

Therefore, the main binder that acts in the spray material of the present invention is an organic binder that forms carbon bonds under heat, and the phosphate and lime compounds act as secondary binders. Although the mechanism of this phenomenon is not clear, the present inventors found that the phenol resin, which is a type of organic binder, and the phosphate and lime compound used together form an agglomerated state in a slurry state with water added. We have confirmed that the slurry has shape-retaining ability, and while this shape-retaining ability is maintained (organic binder O forms carbon bonds, it provides adhesiveness and shape-retaining ability to the construction body). It is estimated that it will be given.

In this way, phenolic resin has the function of forming carbon bonds as an organic binder, and also has the function of imparting shape retention to the slurry through interaction with phosphates and lime compounds. In some cases, the phenolic resin has the effect of suppressing the curing accelerating effect of phosphates caused by lime compounds. That is, in general spray materials, a lime compound is added as a curing accelerator for phosphate, but in the spray material of the present invention, the phosphate and lime compound do not have curing ability.
It forms only weak agglomerates with phenolic resins. This is considered to be because the phenol resin is oriented around the Ca ions dissolved in the slurry via its hydroxyl group or medylol group, forming a kind of complex compound and sequestering the Ca ions. Therefore, if the amount of phenolic resin in the organic binder is less than 40 M%, not only will the aggregation of the slurry become weaker, but the phosphates will harden first and carbon bonds will not be sufficiently formed.

In the present invention, water is added to the slurry by water-cooling the nozzle of the spraying machine used, preventing the organic binder from burning and emitting smoke due to furnace heat, and by interacting with the aforementioned phenolic resin, phosphate, and lime compound. Works effectively for imparting shape retention.

[Example] Examples 1 to 7, Comparative Examples 1 to 6 The trunnion part of the belly of a converter was repaired by spraying 500 kg of the material shown in Table 1 using magnesia as aggregate using a nozzle mix type dry spraying machine. . The construction results and usage results are also shown in the same table.

Examples 8 to 10, Comparative Example 7 200 kg of the bauxite aggregate material shown in Table 2 was sprayed onto the side wall of the ladle in the same manner.

The formulations and added water in Tables 1 and 2 are expressed in parts by weight. The adhesion rate was determined by visual observation, and the service life was determined by the number of times the steel was tapped in the converter or the number of times the ladle received the steel until the sprayed body became residual O.

The feature of the present invention is that in the converter, the adhesion rate is high and the durability is improved, as shown in Examples 1 to 7. This suggests that a dense construction body is formed.

On the other hand, when only an organic binder is used, there is almost no adhesion (
Comparative Example 3), even if a phosphoric acid binder is used, adhesion does not improve unless a lime compound is used (Comparative Example 4). However, if too much of the Table 2 lime compound is used, the durability decreases (Comparative Example 6). In addition, the amount of organic binder is small (Comparative Example 2),
If too much phosphoric acid binder is used (Comparative Example 5), the adhesion rate and durability will not be good. Furthermore, it can be seen that even if the amount of phenolic resin in the organic binder is small (Comparative Example 1), a decrease in durability is observed.

Similar results have also been obtained when the present invention is used in a ladle.

[Effects of the Invention] As detailed above, the spray repair material of the present invention is easy to apply and is inferior to baked-on materials due to the combination of a specific organic binder and lime compound, regardless of the type of fire-resistant material. It is extremely useful in that it provides excellent adhesion and durability.

Claims (1)

[Claims] 40 parts by weight of powdered phenolic resin for 100 parts by weight of fireproof material
5 to 20 parts by weight of organic binder, 0.3 to 4 parts by weight of phosphoric acid binder, and lime compound containing Ca
A spray repair material characterized by containing 2 to 8 parts by weight in terms of O.